One of the most famous British WWII fighter aircraft was the Spitfire developed by R.J. Mitchell. Its maiden flight was March 5, 1936. The Spitfire IX modification featured a more powerful Merlin 66 engine and was in production from 1943-1945. In the summer of 1944 the Spitfire IX was the basis plane for the British Fighter Command. They took part in Operation Overlord. They were also involved in special missions, in particular the delivery of beer to the mainland for the advancing Allied forces.